Need to put back header and menu code

I originally integrated WP into my web site via a iFrame for flexibility. When I did I removed the original WP header and menu bar. Now I am using the Cashie plug-in for e-commerce and when you click the “add to cart” button the iFrame is not supported and the shopping cart opens a page that over rides my web site with no navigation back. I want to replace the WP header and menu bar and have my WP site as my index.html page. In short I want it back to the original WP when I first set it up. Is there a chunk of code that I can just paste in and be back to where I was? Thanks. I think the iFrames were a bad idea.